Scientific Publications


Peer Reviewed Publications



Ramp C, Delarue J, Palsbøll PJ, Sears R, Hammond PS (2015) Adapting to a Warmer Ocean-Seasonal Shift of Baleen Whale Movements over Three Decades. PLoS ONE 10(3): e0121374. doi:10.1371/journal.pone.0121374 (see article here)

Denise Risch, Manuel Castellote, Christopher W. Clark, Genevieve E. Davis, Peter J. Dugan, Lynne EW. Hodge, Anurag Kumar, Klaus Lucke, David K Mellinger, Sharon L. Nieukirk, Cristian Marian Popescu, Christian Ramp, Andrew J. Read, Aaron N. Rice, Monica A. Silva, Ursula Siebert, Kathleen M. Stafford, Hans Verdaat and Sofie M. Van Parijs, 2014. Seasonal migrations of North Atlantic minke whales: novel insights from large-scale passive acoustic monitoring networks. Movement Ecology, 2:24 (see article here)

Brian W. Kot, Richard Sears, Dany Zbinden, Eliabeth Borda and Malcolm S. Gordon, 2014. Rorqual whale (Balaenopteridae) surface lunge-feeding behaviors: Standardized classification, repertoire diversity and evolutionary analyses. Marine Mammal Science, 30(4): 1335–1357 (October 2014) (see article here)

Christian Ramp, Julien Delarue, Martine Bérubé, Philip S. Hammond, Richard Sears. Fin whale survival and abundance in the Gulf of St. lawrence, Canada. Endangered Species Research, Vol. 23: 125-132, 2014

Katherine Gavrilchuk, Véronique Lesage, Christian Ramp, Richard Sears, Martine Bérubé, Stuart Bearhop, Gwénaël Beauplet (2014): Trophic niche partitioning among sympatric baleen whale species following the collapse of groundfish stocks in the Northwest Atlantic. Marine Ecology Progress Series, Vol. 497: 285-301. (see article here)

Richard Sears, Christian Ramp, Annie B. Douglas, John Calambokidis (2013): Reproductive parameters of eastern north Pacific blue whales Balaenoptera musculus. Endangered Species Research, Vol. 22; 23-31.

Christian Ramp and Richard Sears. 2013. Distribution, densities, and annual occurence of individual blue whales (Balaenoptera musculus) in the Gulf of St. Lawrence, Canada from 1980-2008. Canadian Science Advisory Secretariat, Research document 2012/157. (see article here)

Brian W. Kot, Dany Zbinden & Richard Sears (2013): Aerial behavior by the fin whale (Balaenoptera physalus) in the wake of a freighter and near other boats, Marine and Freshwater Behaviour and Physiology, DOI:10.1080/10236244.2013.803695. (see Article here)

Kot, B.W., T. Morisaka, R. Sears, D. Samuelson and C.D. marshall. 2012. Low prevalence of visual impairment in a coastal population of gray seals (Halichoerus grypus) in the Gulf of St. lawrence, Canada. Aquatic Mammals 38:367-371.

Kot, B.W., R. Sears, A. Anis, D.P. Nowacek, J.Gedamke and C.D. Marshall. 2012. Behavioral responses of minke whales (Balaenoptera acutorostrata) to experimental fishing gear in a coastal environment. Journal of Experimental Marine Biology and Ecology 413:13-20. (See Article here)

Ramp, C., W. Hagen, Per Palsboll, M. Bérubé, R. Sears. 2010. Age-related multi-year associations in female humpback whales (Megaptera novaeangliae). Behavioral Ecology and Sociobiology.
64:1563-1576. (See Article here)

Ramp, C., M. Bérubé, Per Palsboll, W. Hagen, R. Sears. 2010. Sex-specific survival in the humpback whale Megaptera novaeangliae in the Gulf of St. Lawrence, Canada. Marine Ecology Progress Series. 400:267-276. (See Article here)

Kot, B. W., C. Ramp and R. Sears, 2009. Decreased feeding ability of a minke whale (Balaenoptera acutorostrata) with entanglement-like injuries. Marine Mammal Science 25:***-*** (See Article here)

Robbins, Jooke, Dan DenDanto, Janie Giard, Simone Panigada, Richard Sears and Margherita Zandarelli.  2007. Photo-ID studies of fin whales in the North Atlantic Ocean and the Mediterranean Sea.  Unpublished report to the Scientific Committee of the International Whaling Commission.  Anchorage, Alaska.  4pp. (See Article here)

Doniol-Valcrose, T., D. Berteaux, P. Larouche and R. Sears. 2007. Influence of thermal fronts on habitat selection by four species of rorqual whales in the Gulf of St. Lawrence. Marine Ecology Progress Series. 335:207-216. (See Article here)

Stevick, P. T., J. Allen, P. J. Clapham, S. K. Katona, F. Larsen, J. Lien, D. K. Mattila, P. J. Palsboll, R. Sears, J. Sigurjonsson, T. D. Smith, G. Vikingsson, N. Oien and P. S. Hammond . 2006. Population spatial structuring on the feeding grounds in North Atlantic humpback whales. Journal of Zoology. 270:244-255. (See Article here).

Berchok, C. L., D. L. Bradley and T. B. Gabrielson. 2006. St. Lawrence blue whale vocalizations revisited: Characterization of calls detected from 1998 to 2001. Journal of Acoustical Society of America . 120(4): 2340-2354. (See Article here).

Bérubé, M., M. Rew, H. Skaug, H. Jørgensen, J. Robbins, R. Sears, and P. Palsbøll. 2005. Polymorphic microsatellite loci isolated from humpback whale, Megaptera novaeangliae and fin whale, Balaenoptera physalus. Conservation Genetics. 6(4): 631-636. (See Article here).

Ramp, C., M. Bérubé, W. Hagen, and R Sears. 2006. Survival of adult blue whales (Balaenoptera musculus) in the Gulf of St. Lawrence, Canada. Marine Ecology Progress Series. 319:287-295. (See Article here).

Coakes, A., S. Gowans, P. Simard, J. Giard, C. Vashro, and R. Sears. 2005. Photographic identification of fin whales (Balaenoptera physalus) off the Atlantic coast of Nova Scotia, Canada. Marine Mammal Science. 21(2):323-326. (See Article here).

Metcalfe, C, Koenig B, Metcalfe T, Paterson G, Sears, R. 2004. Intra- and inter-species differences in persistent organic contaminants in the blubber of blue whales and humpback whales from the Gulf of St. Lawrence. Marine Environmental Research 57:245-260. (See Article here).

Measures, L., B. Roberge, and  R.Sears. 2004. Stranding of a Pygmy Sperm Whale (Kogia breviceps), in the northern Gulf of St. Lawrence, Canada. The Canadian Field-Naturalist. 118(4):495-498.

Naud, M.J., B. Long, J.C. Brêthes, and R. Sears. 2003.  Influences of underwater bottom topography and morphology on minke whale (Balaenoptera acutorostrata) distribution in the Mingan Island, Canada. J. Mar. Biol. Ass. U.K. 83:889-896.

Sears, R. and F. Larsen. 2002. Long range movements of a blue whale (Balaenoptera musculus) between the Gulf of St. Lawrence and West Greenland. Marine Mammal Science 18:281-285.
(See Article here).

Sears R, and J. Calambokidis. 2002. Status of the blue whale, (Balaenoptera musculus), in Canada. Report to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Canadian Wildlife Service, Ottawa, Ontario. (See Report here).

Berubé, M., C.L. Berchok and R. Sears. 2001. Observation of a male-biased sex ratio in the Gulf of St. Lawrence fin whales (Balaenoptera physalus): Temporal, geographical, or group structure segregation? Mar. Mamm. Sci. 17(2):371-380. (See Article here).

Palsboll, P.J., J. Allen, T.H. Andersen, M. Berube, P.J. Clapham, T.P. Federsen, N. Friday, P.S. Hammond, H. Jorgensen, S. Katona, A.H. Larsen, F. Larsen, J. Lien, D.K. Mattila, F.B. Nygaard, J. Robbins, R. Sears, J. Sigurjonsson, T. Smith, R. Sponer, P. Stevick, N. Oien and G. Vikingsson. 2001. Stock structure and composition of the North Atlantic humpback whale, Megaptera novaeangliae. Rep. Int. Whaling Commn. SC/53/NAH11. 

Stevick, P.T., J. Allen, P.J. Clapham, S.K. Katona, F. Larsen, J. Lien, D.K. Mattila, P.J. Palsbøll,  R. Sears, J. Sigurjonsson, T.D. Smith, G. Vikingsson and N. Oien. 2001.  Population spatial structuring on the feeding grounds in North Atlantic humpback whales. Rep. Int. Whal. Commn. SC/53/NAH8.

Moore, M.J., S.D. Berrow, B.A. Jensen, P. Carr, R. Sears, V.J. Rowntree, R. Payne and P.K Hamilton, 1999.  Relative abundance of large whales around South Georgia (1979-1998). Marine Mammal Science. 15(4):1287-1302. (See Article here) .

Gauthier, J., and R. Sears. 1999. Behavioral response of four species of balaenopterid whales to biopsy sampling. Marine Mammal Science 1:85-101. (See Article here).

Palsbøll, P.J., P.J. Clapham, H. Jørgensen, F. Larsen, D.K. Mattila, R. Sears, J. Sigurjónsson, and O. Vasquez. 1998. The value of parallel analysis of uni- and bi-parental inherited loci: the North Atlantic humpback whale (Megaptera novaeangliae). In Karp, A., P.G. Isaac, and D.S. (eds.) Molecular tools for screening biodiversity: Plants and animals, Chapman and Hall, p.426-430.

Berube, M., A. Aguilar, D Dendanto, F. Larsen, G.N Disciara, R. Sears, J. Sigurjonsson, J. Urban and P. J. Palsboll. 1998. Population genetic structure of North Atlantic, Mediterranean Sea and Sea of Cortez fin whales, Balaenoptera physalus (Linnaeus 1758): Analysis of mitochondrial and nuclear loci. Molecular Ecology 7(5):585-599.

Palsbøll, P.J., J. Allen, M. Berube, P.J. Clapham, T.P. Federsen, P.S. Hammond, R. R. Hudson, H. Jergensen, S. Katona, A.H. Larsen, F. Larsen, J. Lien, D.K. Mattila, J. Sigurjonsson, R. Sears, T. Smith, R. Sponer, P. Stevick, and N. Oien. 1997. Genetic tagging of humpback whales. Nature. 388:767-769. (See Article here).

Gauthier, J.M., C.D. Metcalfe and R. Sears. 1997. Validation of the blubber biopsy technique for monitoring of organochlorine contaminants in balaenopterid whales. Marine Environmental Research. 43(3):157-179. (See Abstract here).

Gauthier, J.M., C.D. Metcalfe and R. Sears. 1997. Chlorinated Organic Contaminants in Blubber Biopsies from Northwestern Atlantic Balaenopterid Whales Summering in the Gulf of St Lawrence. Marine Environmental Research. 44(2):201-223. (See Article here).

Valsecchi, E., Palsbøll, P., Hale, P., Glockner-Ferrari, D., Ferrari, M., Clapham, P., Larsen, F., Mattila, D., Sears, R., Sigurjónsson, S., Brown, M., Corkeron, P., and Amos, B. 1997. Microsatellite genetic distances between oceanic populations of the humpback whale (Megaptera novaeangliae). Molecular Biology and Evolution. 14:355-362.

Palsbøll, PJ, Clapham, PJ, Mattila, DK, Larsen, F, Sears, R, Siegismund, HR, Sigurjønsson, J, Vasquez, O, Arctander, P. 1995. Distribution of mtDNA haplotypes in North Atlantic humpback whales: the influence of behaviour on population structure. Marine Ecology Progress Series. 116:1-10.

Sears, R., J.M. Williamson, F. Wenzel, M. Bérubé, D. Gendron and P.W. Jones. 1991. The Photographic identification of the blue whale (Balaenoptera musculus) in the Gulf of St. Lawrence, Canada. I W C Rep. SC/A88/ID23. pp. 335-342.

Sears, R., Williamson, J.M., Wenzel, F.W., Bérubé, M., Gendron, D. and Jones, P. 1990. Photographic identification of the blue whale (Balaenoptera musculus) in the Gulf of St. Lawrence, Canada. In: Individual Recognition of Cetaceans: Use of Photo-Identification and Other Techniques to Estimate Population Parameters.  Philip S. Hammond, Sally A. Mizroch, and Gregory P. Donovan (eds). IWC Rep. Special Issue 12.

Hammond, P.S., Sears, R. and Bérubé, M., 1990. A note on problems in estimating the number of blue whales in the Gulf of St. Lawrence from photo-identification data. In: Individual Recognition of Cetaceans: Use of Photo-Identification and Other Techniques to Estimate Population Parameters.  Philip S. Hammond, Sally A. Mizroch, and Gregory P. Donovan (eds). IWC Rep. Special Issue 12.

Calambokidis, J., Steiger, G.H., Cubbage, J.C., Balcomb, K.C., Ewald, C., Kruse, S., Wells, R. and Sears, R. 1990. Sightings and movements of blue whales off central California 1986-88 from photo-identification of individuals. In: Individual Recognition of Cetaceans: Use of Photo-Identification and Other Techniques to Estimate Population Parameters.  Philip S. Hammond, Sally A. Mizroch, and Gregory P. Donovan (eds). IWC Rep., Special Issue 12.

Lien, J., R. Sears, G.B. Stenson, P.W. Jones, and I-Hsun Ni. 1989.  Right Whales (Eubalaena glacialis) sightings in waters off Newfoundland and Labrador and the Gulf of St. Lawrence 1978-1987. Can. Field Nat. 103:91-93.

Wenzel F., and R. Sears. 1988. A note on killer whales in the Gulf of St. Lawrence, including an account of an attack on a minke whale. In: North Atlantic Killer Whales, eds. Johann Sigurjonsson and Stephen Leatherwood. Rit Fiskideildar, Jour. of Marine Research Institute. Reykjavik, vol. XI. pp. 202-204.

Sears, R. 1987. The photographic identification of individual blue whales (Balaenoptera musculus) in the Sea of Cortez. Cetus, spring 1987. 7(1):14-17.


Selected Oral and Poster Presentations 

Christian Ramp, Julien Delarue, Martine Bérubé, Phil Hammond, and Richard Sears. 2011. Abundance, survival and population trend of fin whales (Balaenoptera physalus) in the Gulf of St. Lawrence, Canada. (see poster here)

Gavrilchuk, K., Lesage, V., Sears, R., Ramp, C. and Beauplet, G.. Long-term niche trends among four species of baleen whales in the Gulf of St. Lawrence, Quebec, Canada. Oral presentation at the 19th Biennial Conference on the Biology of Marine Mammals. Tampa, Florida. December 2, 2011.

Comtois, Sophie; Savenkoff, Claude; Bourassa, Marie-Noëlle; Brêthes, jean-Claude; Sears, Richard. 2009. David contre Goliath, ou l'histoire d'un géant en voie de disparition, le rorqual bleu. Poster presented at the "Forum québécois des sciences de la mer", Université du Québec à Rimouski, Rimouski, Canada. (see poster here)

Sears, Richard; Doniol-Valcroze, Thomas; Berchock, Catherine; Palsbøll, Per; Bendlin, Andrea; Ramp, Christian. 2009. Sex structure and male-male competition in blue whale trios from the North Atlantic or simplya "ménage à trois". Oral presentation to the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Palsbøll, Per; Tison, Jean-Luc; Hammaström, Ingrid; Sears, Richard; Ramp, Christian; Bérubé, Martine. 2009. "False signature" of past population expansions in North Atlantic minke whales mitochondrial control region sequences. Oral presentation to the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Comtois, Sophie; Savenkoff, Claude; Bourassa, Marie-Noëlle; Brêthes, Jean-Claude; Sears, Richard. 2009. Is the change in distribution and abundance of blue whales related to the groundfish collapse in the northern Gulf of St-Lawrence? Oral presentation to the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Ramp, Christian; Delarue, Julien; Palsbøll, Per; Bérubé Martine; Sears, Richard. 2009. Sex specific mortality in balaenopterids? Comparing long-term studies on humpback, fin and blue whales from the Gulf of St-Lawrence, Canada. Poster presented at the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Delarue, Julien; Bérubé Martine; Ramp, Christian; Sears, Richard. 2009. Patterns of associations among fin whales (Balaenoptera physalus) observed in Gulf of St-Lawrence, Canada. Poster presented at the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada. (see poster here)

Paquet, Louis-Frédéric; Delarue, Julien; Ramp, Christian; Sears, Richard. 2009. MICS-PIX: A web-based, multi-species software for the processing, matching, and storaging of digital photo-identification images. Poster presented at the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Gavrilchuk, Katherine; Renaud, Limoilou-Amélie. 2009. Twenty-six years of photo-identification of fin whales (Balaenoptera physalus): summary, trends and comparison with a sympatric species. Poster presented at the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Kot, Brian; Sears, Richard. 2009. New rorqual whale lunge-feeding strategies, behaviors and mechanisms. Poster presented at the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Tison, Jean-Luc; Bérubé Martine; Sears, Richard; Ramp, Christian; Larsen, Finn; Giard, Janie; Palsbøll, Per. 2009. Patterns of genetic variation in North Atlantic blue whales (Balaenoptera musculus): Population diversity, differenciation and demographic history analysis of mitochondrial and nuclear Loci. Poster presented at the Eighteenth Biennal Conference on the Biology of Marine Mammals, Quebec, Canada.

Ramp, Christian; Lusseau, David; Palsbøll, Per; Hagen, Wilhelm; Sears, Richard. 2007. Long-term bonds in female humpback whales (Megaptera novaengliae) in the Gulf of St. Lawrence, Canada? Oral presentation to the Seventeenth Biennial Conference on the Biology of Marine Mammals, Cape Town, South Africa.

Delarue, J., S. Todd, R. Sears and L. Di Lorio. 2007. Use of fin whale (Balaenoptera physalus) vocalizations to determine stock identity and structure; a comparative study of two North Atlantic feeding grounds. Poster presented at the Seventeenth Biennial Conference on the Biology of Marine Mammals, Cape Town, South Africa. (see poster here)

Doniol-Valcroze, T., D. Berteaux and R. Sears. 2006. Multivariate analysis of habitat selection by rorqual whales. Poster presented at the inaugural meeting of the Canadian Society for Ecology and Evolution, Montreal , April 3-4, 2006. (See Poster here).

Doniol-Valcroze, T., D. Berteaux & R. Sears. 2006. Multivariate analysis of habitat selection by rorqual whales in the Gulf of St. Lawrence , Quebec , Canada . Oral presentation to the 16th biennial conference on the biology of marine mammals, San Diego, December 11 – 16, 2005.

Doniol-Valcroze, T., P. Larouche, D. Berteaux and R. Sears. 2005. Influence of thermal fronts on habitat selection by rorqual whales in the Gulf of St. Lawrence . Oral presentation to the 44th Annual Conference of the Canadian Society of Zoologists, Kingston , May 11-14, 2005. 

Conway C.A., L.A. Lyons, R. Sears, J. Calambokidis, N. Kanda, P.C. Gill, and B.P. May. 2005. Global Population Structure of Blue Whales, Balaenoptera musculus , Based on Nuclear Genetic Variation. Poster presented at the Sixteenth Biennial Conference on the Biology of Marine Mammals, San Diego , California .

Sears, R., C.L.K. Burton, and G. Vikingson. 2005. Review of Blue Whale ( Balaenoptera musculus ) Photoidentification Distribution Data in the North Atlantic, Including the First Long-Range Match between Iceland and Mauritania . Poster presented at the Sixteenth Biennial Conference on the Biology of Marine Mammals, San Diego , California . (See Poster here).

Ramp, C., Berube, M., Hagen , W, and Sears, R. 2005 Population Structure and Dynamic of Humpback Whales ( Megaptera novaeangliae ) in the Gulf of St Lawrence, Canada . Poster presented at the Sixteenth Biennial Conference on the Biology of Marine Mammals, San Diego , California, (see poster here)

Berchok, C.L., Bradley, D.L., Gabrielson, T.B., and Sears, R. 2004. Detection of a unique calling pattern during the respiratory cycle of blue whale pairs. J. Acoust. Soc. Am. 116:2613. Oral Presentation. 

Doniol-Valcroze, T. and R. Sears. 2003. Influence of thermal fronts on the distributionand behaviour of four species of rorqual whales from the Gulf of St. Lawrence, Quebec , Canada . Oral presentation to the 15th biennial conference on the biology of marine mammals, Greensboro , December 14 – 19, 2003.

Berchok, C.L., Bradley, D.L., Gabrielson, T.B., and Sears, R. 2003. Comparison of St. Lawrence blue whale vocalizations with field observations. J. Acoust. Soc. Am. 113:2277. Oral Presentation. (See Abstract here).  

Berchok, C.L., Bradley, D.L., Gabrielson, T.B., and Sears, R. 2002. St. Lawrence blue whale (Balaenoptera musculus ) vocalizations. J. Acoust. Soc. Am. 112:2400. Oral Presentation.

Doniol-Valcroze, T., D. Sergeant and R. Sears. 2001. Spatial distribution of rorqual whales from the Gulf of St. Lawrence , Quebec , Canada . Poster presented at the 14th Biennial conference on the biology of marine mammal. Vancouver, CA. December 2001.

Sears, R. C. Ramp, and J. Calambokidis. 2001. Sightings of Blue whale ( B. musculus ) calves and calving intervals for known females in the Sea of Cortez from 1984-2001 and subsequent observations off California . Poster presented at the 14th Biennial conference on the biology of marine mammal. Vancouver, CA. December 2001.

Chandler , T., J. Calambokidis, and R. Sears. 2001. First Report on Sightings of a White Blue Whale. Poster presented at the 14th biennial conference on the Biology of Marine Mammals, Vancouver, Canada , November 28 – December 3, 2001.

Conway, C., L. Lyons, R. Sears, J. Calambokidis, P. Gill and B. May. 2001. Population Structure of the Blue Whale ( Balaenoptera musculus ) Based on Nuclear Genetic Variation. Poster presented at the 14th biennial conference on the Biology of Marine Mammals, Vancouver , Canada , November 28 – December 3, 2001.

Berchok, C.L., Gabrielson, T.B., and Bradley, D.L. 1999. An inexpensive, portable, and rugged system for recording the low-frequency sounds of cetaceans. J. Acoust. Soc. Am. 106:2281. Oral Presentation.

Sears, R., C.L. Berchok, P. Palsboll, T. Doniol-Valcrose, and C. Ramp. 1999. Gender related structure in blue whale ( Balaenoptera musculus ) pairs from eastern Canadian waters. Oral Presentation to the 13th Biennial conference on the biology of marine mammals, Maui , Hawaii Nov28-Dec3 1999.

Koenig, B., T. Metcalfe, C. Metcalfe, J. Stegeman, M. Moore, C. Miller, and R.   Sears. 1999. Monitoring contaminants and biomarker responses in biopsy samples of blue whales. In: Abstracts 13th Biennial conference on the biology of marine mammals, Maui , Hawaii Nov28-Dec3 1999. 

Conway , C., R. Sears and B. May. 1999. Determining Blue Whale ( Balaenoptera musculus ) Population Structure Using Introns Of Conserved Nuclear Genes. Presentation to the 13th biennial conference on the Biology of Marine Mammals, Maui , Hawaii , November 28 – December 3, 1999. 

Palsbøll, P.J., M. Bérubé, P.J. Clapham, D. Dendanto, D. Dietz, T.P. Feddersen, A.C. Heiberg, M. P. Heide-Jørgensen, H. Jørgensen, A. H. Larsen, F. Larsen, L. Lien, D.K. Mattila, G. Notarbartolo di Sciara, J. Sigurjónsson, R. Sears, R. Sponer, N. Øien. 1998. Post-glacial origin and expansion of arctic and temperate cetacean populations in the North Atlantic . Oral Presentation to the World Marine Mammal Science Conference , Monaco . January 20-25, 1998.

Lien, J., Stenson, G. B., Booth, S. and Sears, R. 1987. Ice entrapments of blue whales ( Balaenoptera musculus ) in Newfoundland and Labrador (1978-1987).  In: abstracts from the North Atlantic Marine Mammal Association Conference, March 26-7, 1987, Boston , MA .